The separation and quantification of polynucleotides such as DNA is of critical importance in molecular biology and improved methods are a focus of current interest. One separation method includes size-exclusion chromatography (E. Heftmann, in J. Chromatog. Lib., Vol. 51A, p. A299 (1992)). The disadvantages of this method include low resolution and low capacity. Another separation method is anion exchange chromatography of DNA with tetramethylammonium chloride containing mobile phases as described in European patent application 0 507 591 A2 to Bloch. However, the separation is not strictly size-based, and the resolution is not always adequate. A further disadvantage of methods which rely on binding of anionic DNA includes the required use of high concentrations of nonvolatile salts in the mobile phase; this interferes with subsequent isolation and measurement (e.g. mass spectral analysis) on the separated fragments.
Thus there is a need in the art for a size-based separation process for DNA which has high capacity and resolution, and which does not require use of nonvolatile salts.